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Full text of "Treatise On Applied Analytical Chemistry(Vol-1)"

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Ferro-titanium is prepared by electro-thermal and alumino-thermal
processes from rutile and from iron ores rich in titanium, and serves as a
deoxidising agent in the refining of cast-iron and steel.

1.  Determination of the Titanium.1—0-5 gram of the finely powdered
sample is heated in a platinum crucible and, after cooling, evaporated to
dryness with a few c.c. of hydrofluoric acid.   The residue is then heated
for a short time in the same crucible with 5-7 grams of potassium bisulphate,
the cooled mass taken up in hydrochloric acid (not too dilute) and heated
on the water-bath until solution is complete.    The liquid is made up to
500-600 c.c., mixed with 20-30 c.c. of concentrated sodium bisulphite
solution and heated gently to reduce the iron to ferrous salts (a drop of
the solution should give no appreciable colour with thiocyanate).    When
the reduction is complete and the temperature of the liquid not above
about 40°, an addition is made, in one quantity and with shaking, of 70-
100 c.c. of concentrated ammonia containing in solution 30 grams of potas-
sium cyanide.    The solution is then heated rapidly and kept near to the
boiling point until the precipitate appears white and the supernatant liquid
has assumed a greenish-yellow coloration.    When cold, the liquid is filtered
and the precipitate washed, first with ammoniacal ammonium sulphite
solution and then with hot water.    The moist precipitate is dissolved in
hot, dilute hydrochloric acid and the titanium oxide in the clear solution
precipitated by fresh addition of ammonia.   The precipitate is filtered,
washed, ignited strongly and weighed :   Ti02 X 0-6005 — Ti.

When aluminium occurs along with the titanium, the oxides thus
separated are fused with bisulphate, the fused mass dissolved in hydro-
chloric acid and the titanium separated from the aluminium by means of

2.  Determination of the Carbon.—By direct combustion in a current
of oxygen3 (see Iron, i,b}.

3.  Determination of the Silicon.—0-3-1 gram is disintegrated with
the mixture of sodium carbonate and magnesia (see Ferro-silicon, i, b, p.
195).    When cold, the semi-fused mass is moistened with water, ground
in a mortar and poured into a beaker, the least possible quantity of rinsing
water being used.    The liquid is strongly acidified with hydrochloric acid
—heating being avoided—left for 1-2 hours and then heated on a water-
bath until the liquid becomes perfectly clear.   The solution is evaporated
in presence of sulphuric acid, heated until copious white fumes appear,
diluted when cold and the separated silicon filtered off (see Ferro-silicon, i, b).

4.  Determination of the Manganese, Phosphorus and Sulphur.—
As in ferro-silicon.

* *

1  Von Woldernar Trautmann (Zeitschr. ang. Chem., 1911, p. 877 ; Boernemann and
Schirrmeister (Zeitschr. ang. Chem.,  1911, p. 709).

2  Bellucci and Grass!:   Gazz. .Chim. Ital., 1913, i, p. 570.

3  With products very rich in silica, disintegration in a current of chlorine must be
employed.on